diatom

[dahy-uh-tuh m, -tom]

noun

any of numerous microscopic, unicellular, marine or freshwater algae of the phylum Chrysophyta, having cell walls containing silica.

Origin of diatom

1835–45; < New Latin Diatoma originally a genus name, feminine noun based on Greek diátomos cut in two. See dia-, -tome

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for diatom

Historical Examples of diatom

In fact, the two pass without any sharp boundary into each other, and both present transitions to the Diatom ooze.
Report on the Radiolaria Collected by H.M.S. Challenger During the Years 1873-1876, First Part: Porulosa (Spumellaria and Acantharia)
Ernst Haeckel
The diatom itself may be washed in the same way, if it is not too small.
The Diatomaceae of Philadelphia and Vicinity
Charles Sumner Boyer
This diatom is often found in abundance in the water supplies of cities.
Through a Microscope
Samuel Wells
The little things, he continued, delicately perforating the atmosphere as though selecting a diatom.
Iole
Robert W. Chambers
He turns himself outside in, and makes a temporary stomach, and proceeds to digest the soft parts of the diatom.
Through a Microscope
Samuel Wells

British Dictionary definitions for diatom

diatom

noun

any microscopic unicellular alga of the phylum Bacillariophyta, occurring in marine or fresh water singly or in colonies, each cell having a cell wall made of two halves and impregnated with silicaSee also diatomite

Word Origin for diatom

C19: from New Latin Diatoma (genus name), from Greek diatomos cut in two, from diatemnein to cut through, from dia- + temnein to cut

Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for diatom

1845, coined from Greek diatomos "cut in two," from diatemnein "to cut through," from dia- "through" (see dia-) + temnein "to cut" (see tome). So called because they typically appear to have been cut in half. Related: Diatomic.

diatom in Science

diatom

[dī′ə-tŏm′]

Any of various one-celled aquatic organisms of the class Bacillariophyceae that have hard bivalve shells (called frustules) composed mostly of silica, can perform photosynthesis, and often live in colonies. They make up a large portion of the marine plankton and are an important food source for many aquatic animals. The skeletal remains of diatoms are the main constituent of diatomite.